I recently bought a seven shot, .22 short revolver. The markings on the barrel are "Whitneyville Armory CT USA" Best I can tell, it was made between 1871 and 1875. Serial number 298XX. I have shot this gun, it works as well in 2017 as it did in 1875.

My question is, however, does anyone have any idea how to release the shaft that holds the cylinder? There is no obvious release and every trick I have thought of does not work.

There is a small screw just forward of the trigger. You can see a glimpse of it in the top picture. Remove the screw. The cylinder shaft will pull out with a little nudging from a screwdriver. Nothing to it -- if you know the trick. Yes, I've put at least 150 round of modern .22 short through it with no issues at all. Can't really hit much beyond ten feet, but it was never designed for anything remotely long range. Picked up somewhere that you could buy one in 1880 for $3.20.

By the way nice knowing the original price, but you know that is kinda right in line with todays prices... That 3.20 back then is about 240 bucks today.. about the price of a small 22 today.. I can not imagine expecting to stop someone with that gun.. But all the material and leather it brings in with it probable was a nasty blood poisoning.. With no antiBiotics at the time..

There is a small screw just forward of the trigger. You can see a glimpse of it in the top picture. Remove the screw. The cylinder shaft will pull out with a little nudging from a screwdriver. Nothing to it -- if you know the trick. Yes, I've put at least 150 round of modern .22 short through it with no issues at all. Can't really hit much beyond ten feet, but it was never designed for anything remotely long range. Picked up somewhere that you could buy one in 1880 for $3.20.